Someone

 var myform = document.getElementById('myform');

          for (i=0; i<myform.getElementsByTagName('t').length; i++) {
      
                if (myform.getElementsByTagName('t')[i].getChecked) {
                      
                   var color = myform.getElementsByTagName('t')[i].getValue;
             	   document.getElementById('dialog_body').setStyle({background: color});
          
                 }
       
  	    }